Linked by Thom Holwerda on Fri 18th Jan 2008 20:18 UTC, submitted by SEJeff
"The Intel Open Source Technology Center is pleased to announce the release of version 0.1 of LatencyTOP, a tool for developers to visualize system latencies. Slow servers, skipping audio, jerky video - everyone knows the symptoms of latency. But to know what's really going on in the system, what's causing the latency, and how to fix it... Those are difficult questions without good answers right now. LatencyTOP is a Linux tool for software developers (both kernel and userspace), aimed at identifying where system latency occurs, and what kind of operation/action is causing the latency to happen. By identifying this, developers can then change the code to avoid the worst latency hiccups."
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RE: Technology from the 90's
by diegocg on Sat 19th Jan 2008 12:49
in reply to "Technology from the 90's"
Member since:2005-07-08
RE: Technology from the 90's
by superstoned on Mon 21st Jan 2008 00:21
in reply to "Technology from the 90's"
Member since:2005-07-07
RE[2]: Technology from the 90's
by bgregg on Mon 21st Jan 2008 18:43
in reply to "RE: Technology from the 90's"
Member since:2007-08-04
Dtrace's license is not compatible with the license of the linux kernel. So we have to wait until either Linus decides to go for GPL v3 or Sun allows DTrace to be used in the linux kernel...
You might want to read through the comments here:
http://blogs.sun.com/ahl/entry/dtrace_knockoffs
which was also discussed on osnews here:
http://osnews.com/comments/18388
Based on everything I know about the issue, the actual stopper for DTrace on Linux is Not Invented Here Syndrome. License discussion led to debate about what is or isn't considered a derived work of the kernel, and ways Linux can work around that to include DTrace.
Member since:
2007-08-04
Encouraging customers to look at latencies for performance analysis is really important.
I quickly browsed the code, and it appears that this is implemented by statically defining latency metrics in the kernel. Wow! Was this written a decade ago?
Performance analysis these days is about dynamic tracing using DTrace, which appears in Solaris 10, MacOS X, and other operating systems. DTrace is able to read these latencies and *thousands* more, in *all* layers of the software stack *without* modifying them.
The latencytop engineers need to look at DTrace and not reinvent a wheel that is already obsolete. DTrace does use statically defined trace points at times, but when appropriate and complementary to the dynamic tracing system.
If this tool does get customers to think more carefully about latency metrics, then that will certainly be valuable. All roads lead to DTrace.